Line, microphone or Hi-Z instrument input not working

Our U22 XT has a switch on the backside that is used for selection to use the inputs on the front or the backside of the device. Please check, if the inputs on the front (microphone / instrument) or the line inputs (RCA connectors) on the back are selected.

If you are sure that the correct input is selected but recording still does not work, it might be caused by a security setting blocking audio input. If you use macOS, check this article. If you use Windows, you can read about it here.